State Highway 94, between Knobs Flat and Milford Sound was closed on Tuesday morning and State Highway 6, between Haast and Makarora, was closed on Wednesday morning following a storm earlier this week.
NZTA West Coast area manager Mark Pinner said the major slip at Diana Falls, near Haast, was stabilised enough yesterday for it to be safe for clearance work to be carried out. However, the road could not be reopened.
The Diana Falls slip was estimated to be about 50m high with at least 500 tonnes of debris along the road below.
''Most of the issues on the highway, including the Diana Falls slip, are within a 2km area between the Gates of the Haast Bridge and the Haast Pass Summit. There have also been many debris flows,'' Mr Pinner said.
It was hoped the road could be reopened later today.
Efforts to get State Highway 94 to Milford Sound open again were entirely dependent on weather, NZTA Southland area manager Peter Robinson said.
Forecast bad weather could slow or even halt road-clearing work today, making reopening the road ''a bit of a long shot''.
The Te Anau to Knobs Flat section of the highway reopened on Wednesday and good progress was made on clearing the road through to the Homer Tunnel yesterday.
The road closures left tourists stranded at two holiday spots.
Milford Helicopters pilot Snow Mullally said a group of seven people would be flown out of Milford Lodge this morning.
Four members of the group, from Korea, had driven a camper van to the lodge and hoped to fly out of Queenstown Airport this afternoon, he said.
A Wellington couple were also stuck at Gunns Camp in the Hollyford Valley.
